Personal Communications Services (PCS) technology is expected to revolutionize the communications industry because of its potential to deliver high bandwidth information services to low-power, portable lightweight devices carried by mobile users. There are some obstacles however, that may retard the realization of this potential. For example, PCS technology has evolved to include a multidimensional communications framework that integrates a variety of mobile communications systems and services ranging from Wireless Private Branch Exchanges (WPBX) and Wireless local Area Networks (WLAN) to cellular-type PCS and cordless-type PCS. To wit, systems and services offered or scheduled to be offered under the PCS umbrella are operative at different frequencies of the spectrum, such as the 902-908 MHz frequency band at which some WPBXs operate in direct contrast to other WPBXs designed around the European cordless standards. Similarly some WLAN vendors, such as AT&T GIS, offer wireless hubs (such as WaveLAN) that operate in the 902-928 MHz frequency band in contrast to other vendors, such as Motorola, who use for their WLAN product line (such as Altair) the so-called Wireless In-Building (WIN) evolving standard that is operative at the 18 GHz frequency. The lack of a uniform well-defined standard for PCS products and services may result in a mosaic of incompatible PCS products or services unable to provide seamless communications from one product or service to another. This issue is further complicated by the fact that some PCS network designs that are based on a particular standard, are inoperative with other PCS network designs implementing a different standard. Clearly, it is desirable for PCS systems to have a transmission system that allows transparent spectrum transport such that the same hardware can be used for different air interfaces without modification.
In addition to the flexibility requirement outlined above, backhaul transmission systems for PCS networks must also be economical to allow PCS products and services to be cost-effective in order to fulfill their market potential. Hence, the prior art implementation of connecting every single PCS microcell (picocell) antenna to a base station via a fiber optic cable that is terminated on a lightwave transceiver operative at different air interfaces, is not cost-effective because of the substantial capital outlay (or expenses) required for laying down (or leasing) fiber optic cables especially in urban environments. Thus, a problem of the prior art is lack of a cost-effective backhaul transmission system that provides the flexibility benefits afforded by the transparent transport of a block of spectrum without wired connections from each microcell to a base station.